Answer and explanation;
In 1670 Gabriel Mouton, Vicar of St. Paul’s Church and an astronomer proposed the swing length of a pendulum with a frequency of one beat per second as the unit of length.
In 1791 the Commission of the French Academy of Sciences proposed the name meter to the unit of length. It would equal one tens-millionth of the distance from the North Pole to the equator along the meridian through Paris.It is realistically represented by the distance between two marks on an iron bar kept in Paris.
In 1889 the 1st General Conference on Weights and Measures define the meter as the distance between two lines on a standard bar that made of an alloy of 90%platinum with 10%iridium.
In 1960 the meter was redefined as 1650763.73 wavelengths of orange-red light, in a vacuum, produced by burning the element krypton (Kr-86).
In 1984 the Geneva Conference on Weights and Measures has defined the meter as the distance light travels, in a vacuum, in 1299792458⁄ seconds with time measured by a cesium-133 atomic clock which emits pulses of radiation at very rapid, regular intervals.
Answer:
the orbit of Io around Jupiter causes the tidal heating.
Explanation:
Io's elliptical orbit causes the tidal force to vary as it orbits Jupiter.
Because Jupiter is a very massive planet, it has a very large gravitational pull on its moons, so the side of Io facing the planet is experiencing a greater gravitational pull than the opposite side. This causes a distortion in the shape of the Io, and a friction that causes the tidal heating.
This friction generates heat currents, which is what makes Io the place with the most volcanic activity in the solar system.
HBr is the most powerful and dangerous acid .
Explanation:
A strong acid is one that instantly disunites or grants its protons in suspension. HBr is a strong acid. HBr is powerful than HCl or HF because the overlapping of a 1s-orbital and a 4p-orbital is surprisingly small, thus the binding is weak so splitting is very easy..